YSI IQ SensorNet MIQ/A-MOD Module - Manual (Page 29)

MIQ/(A-)MOD Data transmission
29 ba76021e01 01/2012
4.3 Structure of the information
Sensor data block The datasets of up to 30 sensors (20 IQ S ENSOR N ET sensors and 10
differential sensors) of the IQ S ENSOR N ET are made available to the
Modbus in a sensor data block in the controller of the IQ S ENSOR N ET .
Query and response
telegram
Data transmission takes place via query and response telegrams. The
form of the telegrams is determined by the Modbus RTU protocol.
The Modbus master transmits a query telegram with a Modbus
command to a Modbus slave. The Modbus slave transmits a response
telegram with the requested data from the sensor data block or an error
message.
Supported
Modbus commands
The IQ S ENSOR N ET provides the data block for read access only.
Writing Modbus commands are not carried out.
Modbus commands Command code
Read Input Register 04h
Read Discrete Inputs 02h
Read Holding Register 03h
Read Coils 01h